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    <title>Document</title>
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    <script>
        // let d = new Date();
        // console.log(d.getFullYear());
        // console.log(d.getMonth());
        // console.log(d.getDate());

        Date.prototype.dateFormate = function(){
            let year = this.getFullYear();
            let month = this.getMonth();
            let date = this.getDate();
            return `${year}年${month + 1}月${date}日`
        }

        let d = new Date("1999-10-1");
        let result = d.dateFormate();
        console.log(result);
    </script>
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